1
|
Gookin TE, Chakravorty D, Assmann SM. Influence of expression and purification protocols on Gα biochemical activity: kinetics of plant and mammalian G protein cycles. BIORXIV : THE PREPRINT SERVER FOR BIOLOGY 2024:2023.05.10.540258. [PMID: 37214830 PMCID: PMC10197700 DOI: 10.1101/2023.05.10.540258] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/24/2023]
Abstract
Heterotrimeric G proteins are a class of signal transduction complexes with broad roles in human health and agriculturally important plant traits. In the classic paradigm, guanine nucleotide binding to the Gα subunit regulates the activation status of the complex. Using the Arabidopsis thaliana Gα subunit, GPA1, we developed a rapid StrepII-tag mediated purification method that facilitates isolation of protein with increased enzymatic activities as compared to conventional methods, and is demonstrably also applicable to mammalian Gα subunits. We subsequently utilized domain swaps of GPA1 and human GNAO1 to demonstrate the instability of recombinant GPA1 is a function of the interaction between the Ras and helical domains, and can be partially uncoupled from the rapid nucleotide binding kinetics displayed by GPA1.
Collapse
Affiliation(s)
- Timothy E. Gookin
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
- These authors contributed equally to the article
| | - David Chakravorty
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
- These authors contributed equally to the article
| | - Sarah M. Assmann
- Biology Department, Pennsylvania State University, University Park, Pennsylvania 16802
| |
Collapse
|
2
|
Torres-Rodriguez MD, Lee SG, Roy Choudhury S, Paul R, Selvam B, Shukla D, Jez JM, Pandey S. Structure-function analysis of plant G-protein regulatory mechanisms identifies key Gα-RGS protein interactions. J Biol Chem 2024; 300:107252. [PMID: 38569936 PMCID: PMC11061236 DOI: 10.1016/j.jbc.2024.107252] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 02/09/2024] [Revised: 03/20/2024] [Accepted: 03/28/2024] [Indexed: 04/05/2024] Open
Abstract
Heterotrimeric GTP-binding protein alpha subunit (Gα) and its cognate regulator of G-protein signaling (RGS) protein transduce signals in eukaryotes spanning protists, amoeba, animals, fungi, and plants. The core catalytic mechanisms of the GTPase activity of Gα and the interaction interface with RGS for the acceleration of GTP hydrolysis seem to be conserved across these groups; however, the RGS gene is under low selective pressure in plants, resulting in its frequent loss. Our current understanding of the structural basis of Gα:RGS regulation in plants has been shaped by Arabidopsis Gα, (AtGPA1), which has a cognate RGS protein. To gain a comprehensive understanding of this regulation beyond Arabidopsis, we obtained the x-ray crystal structures of Oryza sativa Gα, which has no RGS, and Selaginella moellendorffi (a lycophyte) Gα that has low sequence similarity with AtGPA1 but has an RGS. We show that the three-dimensional structure, protein-protein interaction with RGS, and the dynamic features of these Gα are similar to AtGPA1 and metazoan Gα. Molecular dynamic simulation of the Gα-RGS interaction identifies the contacts established by specific residues of the switch regions of GTP-bound Gα, crucial for this interaction, but finds no significant difference due to specific amino acid substitutions. Together, our data provide valuable insights into the regulatory mechanisms of plant G-proteins but do not support the hypothesis of adaptive co-evolution of Gα:RGS proteins in plants.
Collapse
Affiliation(s)
| | - Soon Goo Lee
- Department of Molecular & Cellular Biology, Kennesaw State University, Kennesaw, Georgia, USA
| | - Swarup Roy Choudhury
- Donald Danforth Plant Science Center, St Louis, Missouri, USA; Department of Biology, Indian Institute of Science Education and Research, Tirupati, India
| | - Rabindranath Paul
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Balaji Selvam
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Diwakar Shukla
- Department of Chemical and Biomolecular Engineering, University of Illinois at Urbana-Champaign, Urbana, Illinois, USA
| | - Joseph M Jez
- Department of Biology, Washington University in St Louis, St Louis, Missouri, USA
| | - Sona Pandey
- Donald Danforth Plant Science Center, St Louis, Missouri, USA.
| |
Collapse
|
3
|
Power ME, Fernandez NR, Oni OP, Kalia A, Rourke JL. The non-nutritive sweetener sucralose increases β-arrestin signaling at the constitutively active orphan G protein-coupled receptor GPR52. Can J Physiol Pharmacol 2024; 102:116-127. [PMID: 37748201 DOI: 10.1139/cjpp-2023-0199] [Citation(s) in RCA: 2] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 09/27/2023]
Abstract
Non-nutritive sweeteners are popular food additives owing to their low caloric density and powerful sweetness relative to natural sugars. Their lack of metabolism contributes to evidence proclaiming their safety, yet several studies contradict this, demonstrating that sweeteners activate sweet taste G protein-coupled receptors (GPCRs) and elicit deleterious metabolic functions through unknown mechanisms. We hypothesize that activation of GPCRs, particularly orphan receptors due to their abundance in metabolically active tissues, contributes to the biological activity of sweeteners. We quantified the response of 64 orphans to the sweeteners saccharin and sucralose using a high-throughput β-arrestin-2 recruitment assay (PRESTO-Tango). GPR52 was the sole receptor that significantly responded to a mixture of sucralose and saccharin. Subsequent experiments revealed sucralose as the activating sweetener. Activation of GPR52 was concentration-dependent, with an EC50 of 0.23 mmol/L and an Emax of 3.43 ± 0.24 fold change at 4 mmol/L. GPR52 constitutively activates CRE pathways; however, we show that sucralose-induced activation of GPR52 does not further activate this pathway. Identification of this novel sucralose-GPCR interaction supports the notion that sucralose elicits off-target signaling through the activation of GPR52, calling into question sucralose's assumed lack of bioactivity.
Collapse
Affiliation(s)
- Madeline E Power
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Nicholas R Fernandez
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Olaiya Peter Oni
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Aditaya Kalia
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada
| | - Jillian L Rourke
- Department of Chemistry and Biochemistry, Mount Allison University, Sackville, NB, Canada
| |
Collapse
|
4
|
Ham D, Ahn D, Chung C, Chung KY. Isolation and conformational analysis of the Gα α-helical domain. Biochem Biophys Res Commun 2023; 685:149153. [PMID: 37913692 DOI: 10.1016/j.bbrc.2023.149153] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/23/2023] [Accepted: 10/24/2023] [Indexed: 11/03/2023]
Abstract
Heterotrimeric G proteins (G proteins), composed of Gα, Gβ, and Gγ subunits, are the major downstream signaling molecules of the G protein-coupled receptors. Upon activation, Gα undergoes conformational changes both in the Ras-like domain (RD) and the α-helical domain (AHD), leading to the dissociation of Gα from Gβγ and subsequent regulation of downstream effector proteins. Gα RD mediate the most of classical functions of Gα. However, the role of Gα AHD is relatively not well elucidated despite its much higher sequence differences between Gα subtypes than those between Gα RD. Here, we isolated AHD from Gαs, Gαi1, and Gαq to provide tools for examining Gα AHD. We investigated the conformational dynamics of the isolated Gα AHD compared to those of the GDP-bound Gα. The results showed higher local conformational dynamics of Gα AHD not only at the domain interfaces but also in regions further away from the domain interfaces. This finding is consistent with the conformation of Gα AHD in the receptor-bound nucleotide-free state. Therefore, the isolated Gα AHD could provide a platform for studying the functions of Gα AHD, such as identification of the Gα AHD-binding proteins.
Collapse
Affiliation(s)
- Donghee Ham
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Donghoon Ahn
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Chiwoon Chung
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
| |
Collapse
|
5
|
Mohanasundaram B, Pandey S. Moving beyond the arabidopsis-centric view of G-protein signaling in plants. TRENDS IN PLANT SCIENCE 2023; 28:1406-1421. [PMID: 37625950 DOI: 10.1016/j.tplants.2023.07.014] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/16/2022] [Revised: 07/24/2023] [Accepted: 07/28/2023] [Indexed: 08/27/2023]
Abstract
Heterotrimeric G-protein-mediated signaling is a key mechanism to transduce a multitude of endogenous and environmental signals in diverse organisms. The scope and expectations of plant G-protein research were set by pioneering work in metazoans. Given the similarity of the core constituents, G-protein-signaling mechanisms were presumed to be universally conserved. However, because of the enormous diversity of survival strategies and endless forms among eukaryotes, the signal, its interpretation, and responses vary even among different plant groups. Earlier G-protein research in arabidopsis (Arabidopsis thaliana) has emphasized its divergence from Metazoa. Here, we compare recent evidence from diverse plant lineages with the available arabidopsis G-protein model and discuss the conserved and novel protein components, signaling mechanisms, and response regulation.
Collapse
Affiliation(s)
| | - Sona Pandey
- Donald Danforth Plant Science Center, 975 N. Warson Road, St Louis, MO 63132, USA.
| |
Collapse
|
6
|
Structural and Functional Implication of Natural Variants of Gαs. Int J Mol Sci 2023; 24:ijms24044064. [PMID: 36835474 PMCID: PMC9959179 DOI: 10.3390/ijms24044064] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/16/2023] [Revised: 02/09/2023] [Accepted: 02/15/2023] [Indexed: 02/22/2023] Open
Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins) are among the most important cellular signaling components, especially G protein-coupled receptors (GPCRs). G proteins comprise three subunits, Gα, Gβ, and Gγ. Gα is the key subunit, and its structural state regulates the active status of G proteins. Interaction of guanosine diphosphate (GDP) or guanosine triphosphate (GTP) with Gα switches G protein into basal or active states, respectively. Genetic alteration in Gα could be responsible for the development of various diseases due to its critical role in cell signaling. Specifically, loss-of-function mutations of Gαs are associated with parathyroid hormone-resistant syndrome such as inactivating parathyroid hormone/parathyroid hormone-related peptide (PTH/PTHrP) signaling disorders (iPPSDs), whereas gain-of-function mutations of Gαs are associated with McCune-Albright syndrome and tumor development. In the present study, we analyzed the structural and functional implications of natural variants of the Gαs subtype observed in iPPSDs. Although a few tested natural variants did not alter the structure and function of Gαs, others induced drastic conformational changes in Gαs, resulting in improper folding and aggregation of the proteins. Other natural variants induced only mild conformational changes but altered the GDP/GTP exchange kinetics. Therefore, the results shed light on the relationship between natural variants of Gα and iPPSDs.
Collapse
|
7
|
Ohata Y, Kakimoto H, Seki Y, Ishihara Y, Nakano Y, Yamamoto K, Takeyari S, Fujiwara M, Kitaoka T, Takakuwa S, Kubota T, Ozono K. Pathogenic variants of the GNAS gene introduce an abnormal amino acid sequence in the β6 strand/α5 helix of Gsα, causing pseudohypoparathyroidism type 1A and pseudopseudohypoparathyroidism in two unrelated Japanese families. Bone Rep 2022; 17:101637. [PMID: 36407415 PMCID: PMC9668531 DOI: 10.1016/j.bonr.2022.101637] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Submit a Manuscript] [Subscribe] [Scholar Register] [Received: 07/29/2022] [Revised: 11/03/2022] [Accepted: 11/09/2022] [Indexed: 11/11/2022] Open
Abstract
Pseudohypoparathyroidism 1A (PHP1A) and pseudopseudohypoparathyroidism (PPHP) are caused by loss-of-function variants of GNAS, which encodes Gsα. We present two unrelated Japanese families with PHP1A and PPHP harboring unreported pathogenic variants of GNAS (c.1141delG, p.Asp381Thrfs*23 and c.1117delC, p.Arg373Alafs*31). These variants introduce abnormal amino acids in the β6 strand/α5 helix of Gsα, which interact with G protein coupling receptor (GPCR). We conclude that these variants alter the association of Gsα with GPCR and cause PHP1A or PPHP. Reports of GNAS variants causing extra amino acid sequences are limited. Two cases with extended Gsα mutants showed clinical characteristics of PHP1A/PPHP. No change was found in the affinity between mutant Gsα and GDP using I-TASSER. I-TASSER and AlphaFold2 suggested the Gsα mutants caused dysfunction with GPCR. Prediction by I-TASSER and AlphaFold2 are useful in determination of pathogenicity.
Collapse
Affiliation(s)
- Yasuhisa Ohata
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Haruna Kakimoto
- Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yuko Seki
- Department of Pediatrics, Kagoshima University Graduate School of Medical and Dental Sciences, Kagoshima, Japan
| | - Yasuki Ishihara
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
- The first Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Suita, Japan
- Department of Cardiovascular Medicine, Osaka University Graduate School of Medicine, Suita, Japan
| | - Yukako Nakano
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Kenichi Yamamoto
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Statistical Genetics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Shinji Takeyari
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Makoto Fujiwara
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
- The first Department of Oral and Maxillofacial Surgery, Osaka University Graduate School of Dentistry, Suita, Japan
| | - Taichi Kitaoka
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Satoshi Takakuwa
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
- Department of Pediatrics, Hyogo Prefectural Nishinomiya Hospital, Japan
| | - Takuo Kubota
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| | - Keiichi Ozono
- Department of Pediatrics, Osaka University Graduate School of Medicine, Suita, Japan
| |
Collapse
|
8
|
Liu Y, Wang X, Lv H, Cao M, Li Y, Yuan X, Zhang X, Guo YD, Zhang N. Anabolism and signaling pathways of phytomelatonin. JOURNAL OF EXPERIMENTAL BOTANY 2022; 73:5801-5817. [PMID: 35430630 DOI: 10.1093/jxb/erac158] [Citation(s) in RCA: 6] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/16/2022] [Accepted: 04/13/2022] [Indexed: 06/14/2023]
Abstract
Phytomelatonin is a small multifunctional molecule found ubiquitously in plants, which plays an important role in plant growth, development, and biotic and abiotic stress responses. The classical biosynthetic and metabolic pathways of phytomelatonin have been elucidated, and uncovering alternative pathways has deepened our understanding of phytomelatonin synthesis. Phytomelatonin functions mainly via two pathways. In the direct pathway, phytomelatonin mediates the stress-induced reactive oxygen species burst through its strong antioxidant capacity. In the indirect pathway, phytomelatonin acts as a signal to activate signaling cascades and crosstalk with other plant hormones. The phytomelatonin receptor PMTR1/CAND2 was discovered in 2018, which enhanced our understanding of phytomelatonin function. This review summarizes the classical and potential pathways involved in phytomelatonin synthesis and metabolism. To elucidate the functions of phytomelatonin, we focus on the crosstalk between phytomelatonin and other phytohormones. We propose two models to explain how PMTR1 transmits the phytomelatonin signal through the G protein and MAPK cascade. This review will facilitate the identification of additional signaling molecules that function downstream of the phytomelatonin signaling pathway, thus improving our understanding of phytomelatonin signal transmission.
Collapse
Affiliation(s)
- Ying Liu
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xiaoyun Wang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Hongmei Lv
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Meng Cao
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Yongchong Li
- College of Horticulture, China Agricultural University, Beijing, 100193, China
| | - Xiaowei Yuan
- Huasheng Agriculture Co. Ltd, Qingzhou, Shandong, 262500, China
| | - Xichun Zhang
- School of Plant Science and Technology, Beijing Agricultural University, Beijing, 102206, China
| | - Yang-Dong Guo
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- Sanya Institute of China Agricultural University, Sanya, 572000, China
| | - Na Zhang
- College of Horticulture, China Agricultural University, Beijing, 100193, China
- Sanya Institute of China Agricultural University, Sanya, 572000, China
| |
Collapse
|
9
|
Effect of α-helical domain of Gi/o α subunit on GDP/GTP turnover. Biochem J 2022; 479:1843-1855. [PMID: 36000572 DOI: 10.1042/bcj20220163] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/04/2022] [Revised: 08/11/2022] [Accepted: 08/24/2022] [Indexed: 11/17/2022]
Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins) are composed of α, β, and γ subunits, and Gα has a GDP/GTP-binding pocket. When a guanine nucleotide exchange factor (GEF) interacts with Gα, GDP is released, and GTP interacts to Gα. The GTP-bound activated Gα dissociates from GEF and Gβγ, mediating the induction of various intracellular signaling pathways. Depending on the sequence similarity and cellular function, Gα subunits are subcategorized into four subfamilies: Gαi/o, Gαs, Gαq/11, and Gα12/13. Although the Gαi/o subtype family proteins, Gαi3 and GαoA, share similar sequences and functions, they differ in their GDP/GTP turnover profiles, with GαoA possessing faster rates than Gαi3. The structural factors responsible for these differences remain unknown. In this study, we employed hydrogen/deuterium exchange mass spectrometry and mutational studies to investigate the factors responsible for these functional differences. The Gα subunit consists of a Ras-like domain (RD) and an α-helical domain (AHD). The RD has GTPase activity and receptor-binding and effector-binding regions; however, the function of the AHD has not yet been extensively studied. In this study, the chimeric construct containing the RD of Gαi3 and the AHD of GαoA showed a GDP/GTP turnover profile similar to that of GαoA, suggesting that the AHD is the major regulator of the GDP/GTP turnover profile. Additionally, site-directed mutagenesis revealed the importance of the N-terminal part of αA and αA/αB loops in the AHD for the GDP/GTP exchange. These results suggest that the AHD regulates the nucleotide exchange rate within the Gα subfamily.
Collapse
|
10
|
Petutschnig E, Anders J, Stolze M, Meusel C, Hacke R, Much L, Schwier M, Gippert AL, Kroll S, Fasshauer P, Wiermer M, Lipka V. EXTRA LARGE G-PROTEIN2 mediates cell death and hyperimmunity in the chitin elicitor receptor kinase 1-4 mutant. PLANT PHYSIOLOGY 2022; 189:2413-2431. [PMID: 35522044 PMCID: PMC9342992 DOI: 10.1093/plphys/kiac214] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/05/2022] [Accepted: 04/13/2022] [Indexed: 05/08/2023]
Abstract
Heterotrimeric G-proteins are signal transduction complexes that comprised three subunits, Gα, Gβ, and Gγ, and are involved in many aspects of plant life. The noncanonical Gα subunit EXTRA LARGE G-PROTEIN2 (XLG2) mediates pathogen-associated molecular pattern (PAMP)-induced reactive oxygen species (ROS) generation and immunity downstream of pattern recognition receptors. A mutant of the chitin receptor component CHITIN ELICITOR RECEPTOR KINASE1 (CERK1), cerk1-4, maintains normal chitin signaling capacity but shows excessive cell death upon infection with powdery mildew fungi. We identified XLG2 mutants as suppressors of the cerk1-4 phenotype. Mutations in XLG2 complex partners ARABIDOPSIS Gβ1 (AGB1) and Gγ1 (AGG1) have a partial cerk1-4 suppressor effect. Contrary to its role in PAMP-induced immunity, XLG2-mediated control of ROS production by RESPIRATORY BURST OXIDASE HOMOLOGUE D (RBOHD) is not critical for cerk1-4-associated cell death and hyperimmunity. The cerk1-4 phenotype is also independent of the co-receptor/adapter kinases BRI1-ASSOCIATED RECEPTOR KINASE 1 (BAK1) and SUPPRESSOR OF BIR1 1 (SOBIR1), but requires the E3 ubiquitin ligase PLANT U-BOX 2 (PUB2). XLG2 localizes to both the cell periphery and nucleus, and the cerk1-4 cell death phenotype is mediated by the cell periphery pool of XLG2. Integrity of the XLG2 N-terminal domain, but not its phosphorylation, is essential for correct XLG2 localization and formation of the cerk1-4 phenotype. Our results support a model in which XLG2 acts downstream of an unknown cell surface receptor that activates an NADPH oxidase-independent cell death pathway in Arabidopsis (Arabidopsis thaliana).
Collapse
Affiliation(s)
| | - Julia Anders
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Marnie Stolze
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Christopher Meusel
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Ronja Hacke
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Laura Much
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Melina Schwier
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Anna-Lena Gippert
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Samuel Kroll
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | - Patrick Fasshauer
- Department of Plant Cell Biology, Albrecht-von-Haller-Institute for Plant Sciences, Georg-August-University Göttingen, Göttingen 37077, Germany
| | | | | |
Collapse
|
11
|
Mohanasundaram B, Dodds A, Kukshal V, Jez JM, Pandey S. Distribution and the evolutionary history of G-protein components in plant and algal lineages. PLANT PHYSIOLOGY 2022; 189:1519-1535. [PMID: 35377452 PMCID: PMC9237705 DOI: 10.1093/plphys/kiac153] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/19/2021] [Accepted: 03/08/2022] [Indexed: 05/25/2023]
Abstract
Heterotrimeric G-protein complexes comprising Gα-, Gβ-, and Gγ-subunits and the regulator of G-protein signaling (RGS) are conserved across most eukaryotic lineages. Signaling pathways mediated by these proteins influence overall growth, development, and physiology. In plants, this protein complex has been characterized primarily from angiosperms with the exception of spreading-leaved earth moss (Physcomitrium patens) and Chara braunii (charophytic algae). Even within angiosperms, specific G-protein components are missing in certain species, whereas unique plant-specific variants-the extra-large Gα (XLGα) and the cysteine-rich Gγ proteins-also exist. The distribution and evolutionary history of G-proteins and their function in nonangiosperm lineages remain mostly unknown. We explored this using the wealth of available sequence data spanning algae to angiosperms representing extant species that diverged approximately 1,500 million years ago, using BLAST, synteny analysis, and custom-built Hidden Markov Model profile searches. We show that a minimal set of components forming the XLGαβγ trimer exists in the entire land plant lineage, but their presence is sporadic in algae. Additionally, individual components have distinct evolutionary histories. The XLGα exhibits many lineage-specific gene duplications, whereas Gα and RGS show several instances of gene loss. Similarly, Gβ remained constant in both number and structure, but Gγ diverged before the emergence of land plants and underwent changes in protein domains, which led to three distinct subtypes. These results highlight the evolutionary oddities and summarize the phyletic patterns of this conserved signaling pathway in plants. They also provide a framework to formulate pertinent questions on plant G-protein signaling within an evolutionary context.
Collapse
Affiliation(s)
| | - Audrey Dodds
- Donald Danforth Plant Science Center, St Louis, Missouri 63132, USA
| | - Vandna Kukshal
- Department of Biology, Washington University, St Louis, Missouri 63130, USA
| | - Joseph M Jez
- Department of Biology, Washington University, St Louis, Missouri 63130, USA
| | | |
Collapse
|
12
|
Bosch DE, Jeck WR, Siderovski DP. Self-activating G protein α subunits engage seven-transmembrane Regulator of G protein Signaling (RGS) proteins and a Rho guanine nucleotide exchange factor effector in the amoeba Naegleria fowleri. J Biol Chem 2022; 298:102167. [PMID: 35738399 PMCID: PMC9283941 DOI: 10.1016/j.jbc.2022.102167] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/16/2022] [Revised: 06/15/2022] [Accepted: 06/16/2022] [Indexed: 11/17/2022] Open
Abstract
The free-living amoeba Naegleria fowleri is a causative agent of primary amoebic meningoencephalitis and is highly resistant to current therapies, resulting in mortality rates >97%. As many therapeutics target G protein-centered signal transduction pathways, further understanding the functional significance of G protein signaling within N. fowleri should aid future drug discovery against this pathogen. Here, we report that the N. fowleri genome encodes numerous transcribed G protein signaling components, including G protein-coupled receptors (GPCRs), heterotrimeric G protein subunits, Regulator of G protein Signaling (RGS) proteins, and candidate Gα effector proteins. We found N. fowleri Gα subunits have diverse nucleotide cycling kinetics; Nf Gα5 and Gα7 exhibit more rapid nucleotide exchange than GTP hydrolysis (i.e. "self-activating" behavior). A crystal structure of Nf Gα7 highlights the stability of its nucleotide-free state, consistent with its rapid nucleotide exchange. Variations in the phosphate binding loop (P-loop) also contribute to nucleotide cycling differences among Gα subunits. Similar to plant G protein signaling pathways, N. fowleri Gα subunits selectively engage members of a large seven-transmembrane RGS protein family, resulting in acceleration of GTP hydrolysis. We show Nf Gα2 and Gα3 directly interact with a candidate Gα effector protein, RGS-RhoGEF, similar to mammalian Gα12/13 signaling pathways. We demonstrate Nf Gα2 and Gα3 each engage RGS-RhoGEF through a canonical Gα/RGS domain interface, suggesting a shared evolutionary origin with G protein signaling in the enteric pathogen Entamoeba histolytica. These findings further illuminate the evolution of G protein signaling and identify potential targets of pharmacological manipulation in Naegleria fowleri.
Collapse
Affiliation(s)
- Dustin E Bosch
- Department of Pathology, Roy J. and Lucille A. Carver College of Medicine, University of Iowa, Iowa City, Iowa, USA.
| | - William R Jeck
- Department of Pathology, Duke University School of Medicine, Durham, North Carolina, USA
| | - David P Siderovski
- Department of Pharmacology & Neuroscience, University of North Texas Health Science Center, Fort Worth, Texas, USA
| |
Collapse
|
13
|
Gawande ND, Hamiditabar Z, Brunetti SC, Gulick PJ. Characterization of the heterotrimeric G protein gene families in Triticum aestivum and related species. 3 Biotech 2022; 12:99. [PMID: 35463045 PMCID: PMC8938547 DOI: 10.1007/s13205-022-03156-9] [Citation(s) in RCA: 2] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/31/2021] [Accepted: 03/01/2022] [Indexed: 11/27/2022] Open
Abstract
This study characterizes the heterotrimeric G protein gene families in Triticum aestivum, their tissue-specific expression patterns during development and in response to biotic and abiotic stress conditions. There are three Gα genes, three Gβ and 12 Gγ genes, totaling 18 genes encoding heterotrimeric G proteins in the hexaploid wheat genome. Each haploid genome of the hexaploid T. aestivum has a single gene encoding the α subunit of the heterotrimeric G protein complex, GA1, a single Gβ and four Gγ genes. Each gene has three homeologous copies in the A, B and D genomes. The physical interaction between the Gβ (Gpb) and two Gγ subunits, Gpg1 and Gpg2, was shown through bimolecular fluorescence complementation (BiFC). The gene expression in response to biotic and abiotic stresses showed both up-regulation and down-regulation of members of the gene families. Gγ2-B and Gγ2-D are significantly upregulated during heat stress, GA1-D is upregulated by cold stress and Gγ1-A and Gγ1-D were upregulated by Fusarium graminearum inoculation in a F. graminearum resistant cultivar. This suggests that these members may play roles in biotic and abiotic signaling pathways and the roles of these genes within these pathways need further investigation. Supplementary Information The online version contains supplementary material available at 10.1007/s13205-022-03156-9.
Collapse
Affiliation(s)
- Nilesh D. Gawande
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, QB H4B 1R6 Canada
| | - Zeynab Hamiditabar
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, QB H4B 1R6 Canada
| | - Sabrina C. Brunetti
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, QB H4B 1R6 Canada
| | - Patrick J. Gulick
- Biology Department, Concordia University, 7141 Sherbrooke W, Montreal, QB H4B 1R6 Canada
| |
Collapse
|
14
|
Tiwari R, Bisht NC. The multifaceted roles of heterotrimeric G-proteins: lessons from models and crops. PLANTA 2022; 255:88. [PMID: 35304667 DOI: 10.1007/s00425-022-03868-5] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/02/2021] [Accepted: 03/04/2022] [Indexed: 06/14/2023]
Abstract
The review summarizes our advanced understanding of the heterotrimeric G-protein research from model plants and their emerging roles in modulating various plant architecture and agronomical traits in crop species. Heterotrimeric G-proteins (hereafter G-proteins), consisting of G-alpha (Gα), G-beta (Gβ) and G-gamma (Gγ) subunits, are key signal transducers conserved across different forms of life. The discovery of plant lineage-specific G-protein components (extra-large G-proteins and type-C Gγ subunits), inherent polyploidy in angiosperms, and unique modes of G-protein cycle regulation in plants pointed out to a few fundamental differences of plant G-protein signaling from its animal counterpart. Over the last 2 decades, extensive studies in the model plant Arabidopsis thaliana have confirmed the involvement of G-proteins in a wide range of plant growth and development, and stress adaptation processes. The G-protein research in crop species, however, is still in its infancy, and a handful of studies suggest important roles of G-proteins in regulating plant architectural and key agronomical traits including plant's response to abiotic and biotic factors. We propose that the advancement made in plant G-proteins research will facilitate the development of novel approaches to manage plant yield and fitness in changing environments.
Collapse
Affiliation(s)
- Ruchi Tiwari
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India
| | - Naveen C Bisht
- National Institute of Plant Genome Research (NIPGR), Aruna Asaf Ali Marg, New Delhi, 110067, India.
| |
Collapse
|
15
|
Ghusinga KR, Elston TC, Jones AM. Towards resolution of a paradox in plant G-protein signaling. PLANT PHYSIOLOGY 2022; 188:807-815. [PMID: 34791482 PMCID: PMC8825252 DOI: 10.1093/plphys/kiab534] [Citation(s) in RCA: 8] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 07/16/2021] [Accepted: 10/17/2021] [Indexed: 05/20/2023]
Abstract
G-proteins are molecular on-off switches that are involved in transmitting a variety of extracellular signals to their intracellular targets. In animal and yeast systems, the switch property is encoded through nucleotides: a GDP-bound state is the "off-state" and the GTP-bound state is the "on-state". The G-protein cycle consists of the switch turning on through nucleotide exchange facilitated by a G-protein coupled receptor and the switch turning off through hydrolysis of GTP back to GDP, facilitated by a protein designated REGULATOR OF G SIGNALING 1 (RGS). In plants, G-protein signaling dramatically differs from that in animals and yeast. Despite stringent conservation of the nucleotide binding and catalytic structures over the 1.6 billion years that separate the evolution of plants and animals, genetic and biochemical data indicate that nucleotide exchange is less critical for this switch to operate in plants. Also, the loss of the single RGS protein in Arabidopsis (Arabidopsis thaliana) confers unexpectedly weaker phenotypes consistent with a diminished role for the G cycle, at least under static conditions. However, under dynamic conditions, genetic ablation of RGS in Arabidopsis results in a strong phenotype. We explore explanations to this conundrum by formulating a mathematical model that takes into account the accruing evidence for the indispensable role of phosphorylation in G-protein signaling in plants and that the G-protein cycle is needed to process dynamic signal inputs. We speculate that the plant G-protein cycle and its attendant components evolved to process dynamic signals through signaling modulation rather than through on-off, switch-like regulation of signaling. This so-called change detection may impart greater fitness for plants due to their sessility in a dynamic light, temperature, and pest environment.
Collapse
Affiliation(s)
- Khem Raj Ghusinga
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, North Carolina, USA
- Computational Medicine Program, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Timothy C Elston
- Department of Pharmacology, University of North Carolina at Chapel Hill, North Carolina, USA
- Computational Medicine Program, University of North Carolina at Chapel Hill, North Carolina, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina at Chapel Hill, North Carolina, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, North Carolina, USA
- Author for communication:
| |
Collapse
|
16
|
Pandey S, Harline K, Choudhury SR. Modification of G-protein biochemistry and its effect on plant/environment interaction. Methods Enzymol 2022; 676:307-324. [DOI: 10.1016/bs.mie.2022.06.006] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/17/2022]
|
17
|
Ahn D, Chung KY. The Conformational Dynamics of Heterotrimeric G Proteins During GPCR-Mediated Activation. Subcell Biochem 2022; 99:271-284. [PMID: 36151379 DOI: 10.1007/978-3-031-00793-4_8] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 06/16/2023]
Abstract
Heterotrimeric G proteins (G proteins) are essential cellular signaling proteins that mediate extracellular signals to achieve various cellular functions. G-protein-coupled receptors (GPCRs) are the major guanine nucleotide exchange factors (GEFs) that induce G proteins to release guanosine diphosphate and rapidly bind to guanosine triphosphate, resulting in G protein activation. G proteins undergo dynamic conformational changes during the activation/inactivation process, and the precise structural mechanism of GPCR-mediated G protein activation is of great interest. Over the last decade, a number of GPCR-G protein complex structures have been identified, yet an understanding of the mechanisms underlying allosteric conformational changes during receptor-mediated G protein activation and GPCR-G protein coupling selectivity is only now emerging. This review discusses recent studies on the dynamic conformational changes of G proteins and provides insight into the structural mechanism of GPCR-mediated G protein activation.
Collapse
Affiliation(s)
- Donghoon Ahn
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea
| | - Ka Young Chung
- School of Pharmacy, Sungkyunkwan University, Suwon, Republic of Korea.
| |
Collapse
|
18
|
Maruta N, Trusov Y, Jones AM, Botella JR. Heterotrimeric G Proteins in Plants: Canonical and Atypical Gα Subunits. Int J Mol Sci 2021; 22:11841. [PMID: 34769272 PMCID: PMC8584482 DOI: 10.3390/ijms222111841] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/06/2021] [Revised: 10/26/2021] [Accepted: 10/27/2021] [Indexed: 11/16/2022] Open
Abstract
Heterotrimeric GTP-binding proteins (G proteins), consisting of Gα, Gβ and Gγ subunits, transduce signals from a diverse range of extracellular stimuli, resulting in the regulation of numerous cellular and physiological functions in Eukaryotes. According to the classic G protein paradigm established in animal models, the bound guanine nucleotide on a Gα subunit, either guanosine diphosphate (GDP) or guanosine triphosphate (GTP) determines the inactive or active mode, respectively. In plants, there are two types of Gα subunits: canonical Gα subunits structurally similar to their animal counterparts and unconventional extra-large Gα subunits (XLGs) containing a C-terminal domain homologous to the canonical Gα along with an extended N-terminal domain. Both Gα and XLG subunits interact with Gβγ dimers and regulator of G protein signalling (RGS) protein. Plant G proteins are implicated directly or indirectly in developmental processes, stress responses, and innate immunity. It is established that despite the substantial overall similarity between plant and animal Gα subunits, they convey signalling differently including the mechanism by which they are activated. This review emphasizes the unique characteristics of plant Gα subunits and speculates on their unique signalling mechanisms.
Collapse
Affiliation(s)
- Natsumi Maruta
- School of Agriculture and Food Sciences, University of Queensland, Brisbane 4072, Australia; (N.M.); (Y.T.)
| | - Yuri Trusov
- School of Agriculture and Food Sciences, University of Queensland, Brisbane 4072, Australia; (N.M.); (Y.T.)
| | - Alan M. Jones
- Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA;
- Departments of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jose R. Botella
- School of Agriculture and Food Sciences, University of Queensland, Brisbane 4072, Australia; (N.M.); (Y.T.)
| |
Collapse
|
19
|
Genome‑wide characterization of the Gα subunit gene family in Rosaceae and expression analysis of PbrGPAs under heat stress. Gene 2021; 810:146056. [PMID: 34732368 DOI: 10.1016/j.gene.2021.146056] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/23/2021] [Revised: 09/23/2021] [Accepted: 10/28/2021] [Indexed: 11/23/2022]
Abstract
The Gα subunit is an important component of the heterotrimeric G-protein complex and an integral component of several signal transduction pathways. It plays crucial roles in the diverse processes of plant growth and development, including the response to abiotic stress, regulation of root development, involvement in stomatal movement, and participation in hormone responses, which have been well investigated in many species. However, no comprehensive analysis has identified and explored the evolution, expression pattern characteristics and heat stress response of the Gα subunit genes in Rosaceae. In this study, 52 Gα subunit genes were identified in eight Rosaceae species; these genes were divided into three subfamilies (I, II, and III) based on their phylogenetic, conserved motif, and structural characteristics. Whole genome and dispersed duplication events were found to have contributed significantly to the expansion of the Gα subunit gene family, and purifying selection to have played a key role in the evolution of Gα subunit genes. An expression analysis identified some PbrGPA genes that were highly expressed in leaf, root, and fruit, and exhibited diverse spatiotemporal expression models in pear. Under abiotic stress conditions, the mRNA transcript levels of PbrGPA genes were up-regulated in response to high temperature treatment in leaves. Furthermore, three Gα subunit genes were shown to be located in the plasma membrane and nucleus in pear. In conclusion, the study of the Gα subunit gene family will help us to better understand its evolutionary history and expression patterns, while facilitating further investigations into the function of the Gα subunit gene in response to heat stress.
Collapse
|
20
|
Research Advances in Heterotrimeric G-Protein α Subunits and Uncanonical G-Protein Coupled Receptors in Plants. Int J Mol Sci 2021; 22:ijms22168678. [PMID: 34445383 PMCID: PMC8395518 DOI: 10.3390/ijms22168678] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/08/2021] [Revised: 08/05/2021] [Accepted: 08/10/2021] [Indexed: 12/22/2022] Open
Abstract
As crucial signal transducers, G-proteins and G-protein-coupled receptors (GPCRs) have attracted increasing attention in the field of signal transduction. Research on G-proteins and GPCRs has mainly focused on animals, while research on plants is relatively rare. The mode of action of G-proteins is quite different from that in animals. The G-protein α (Gα) subunit is the most essential member of the G-protein signal cycle in animals and plants. The G-protein is activated when Gα releases GDP and binds to GTP, and the relationships with the GPCR and the downstream signal are also achieved by Gα coupling. It is important to study the role of Gα in the signaling pathway to explore the regulatory mechanism of G-proteins. The existence of a self-activated Gα in plants makes it unnecessary for the canonical GPCR to activate the G-protein by exchanging GDP with GTP. However, putative GPCRs have been found and proven to play important roles in G-protein signal transduction. The unique mode of action of G-proteins and the function of putative GPCRs in plants suggest that the same definition used in animal research cannot be used to study uncanonical GPCRs in plants. This review focuses on the different functions of the Gα and the mode of action between plants and animals as well as the functions of the uncanonical GPCR. This review employs a new perspective to define uncanonical GPCRs in plants and emphasizes the role of uncanonical GPCRs and Gα subunits in plant stress resistance and agricultural production.
Collapse
|
21
|
Watkins JM, Ross-Elliott TJ, Shan X, Lou F, Dreyer B, Tunc-Ozdemir M, Jia H, Yang J, Oliveira CC, Wu L, Trusov Y, Schwochert TD, Krysan P, Jones AM. Differential regulation of G protein signaling in Arabidopsis through two distinct pathways that internalize AtRGS1. Sci Signal 2021; 14:14/695/eabe4090. [PMID: 34376571 DOI: 10.1126/scisignal.abe4090] [Citation(s) in RCA: 7] [Impact Index Per Article: 2.3] [Reference Citation Analysis] [Abstract] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022]
Abstract
In animals, endocytosis of a seven-transmembrane GPCR is mediated by arrestins to propagate or arrest cytoplasmic G protein-mediated signaling, depending on the bias of the receptor or ligand, which determines how much one transduction pathway is used compared to another. In Arabidopsis thaliana, GPCRs are not required for G protein-coupled signaling because the heterotrimeric G protein complex spontaneously exchanges nucleotide. Instead, the seven-transmembrane protein AtRGS1 modulates G protein signaling through ligand-dependent endocytosis, which initiates derepression of signaling without the involvement of canonical arrestins. Here, we found that endocytosis of AtRGS1 initiated from two separate pools of plasma membrane: sterol-dependent domains and a clathrin-accessible neighborhood, each with a select set of discriminators, activators, and candidate arrestin-like adaptors. Ligand identity (either the pathogen-associated molecular pattern flg22 or the sugar glucose) determined the origin of AtRGS1 endocytosis. Different trafficking origins and trajectories led to different cellular outcomes. Thus, in this system, compartmentation with its associated signalosome architecture drives biased signaling.
Collapse
Affiliation(s)
- Justin M Watkins
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Timothy J Ross-Elliott
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Xiaoyi Shan
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Fei Lou
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Bernd Dreyer
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Meral Tunc-Ozdemir
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Haiyan Jia
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Jing Yang
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Celio Cabral Oliveira
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Biochemistry and Molecular Biology/Bioagro, Universidade Federal de Viçosa, Viçosa, MG, Brazil
| | - Luguang Wu
- School of Agriculture and Food Science, University of Queensland, St. Lucia, Queensland Q4072, Australia
| | - Yuri Trusov
- School of Agriculture and Food Science, University of Queensland, St. Lucia, Queensland Q4072, Australia
| | - Timothy D Schwochert
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Patrick Krysan
- Department of Horticulture, University of Wisconsin Madison, Madison, WI 53706, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA. .,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| |
Collapse
|
22
|
Maruta N, Trusov Y, Urano D, Chakravorty D, Assmann SM, Jones AM, Botella JR. GTP binding by Arabidopsis extra-large G protein 2 is not essential for its functions. PLANT PHYSIOLOGY 2021; 186:1240-1253. [PMID: 33729516 PMCID: PMC8195506 DOI: 10.1093/plphys/kiab119] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 02/10/2021] [Accepted: 02/19/2021] [Indexed: 05/06/2023]
Abstract
The extra-large guanosine-5'-triphosphate (GTP)-binding protein 2, XLG2, is an unconventional Gα subunit of the Arabidopsis (Arabidopsis thaliana) heterotrimeric GTP-binding protein complex with a major role in plant defense. In vitro biochemical analyses and molecular dynamic simulations show that affinity of XLG2 for GTP is two orders of magnitude lower than that of the conventional Gα, AtGPA1. Here we tested the physiological relevance of GTP binding by XLG2. We generated an XLG2(T476N) variant with abolished GTP binding, as confirmed by in vitro GTPγS binding assay. Yeast three-hybrid, bimolecular fluorescence complementation, and split firefly-luciferase complementation assays revealed that the nucleotide-depleted XLG2(T476N) retained wild-type XLG2-like interactions with the Gβγ dimer and defense-related receptor-like kinases. Both wild-type and nucleotide-depleted XLG2(T476N) restored the defense responses against Fusarium oxysporum and Pseudomonas syringae compromised in the xlg2 xlg3 double mutant. Additionally, XLG2(T476N) was fully functional restoring stomatal density, root growth, and sensitivity to NaCl, but failed to complement impaired germination and vernalization-induced flowering. We conclude that XLG2 is able to function in a GTP-independent manner and discuss its possible mechanisms of action.
Collapse
Affiliation(s)
- Natsumi Maruta
- Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
- School of Chemistry and Molecular Biosciences, Institute for Molecular Bioscience and Australian Infectious Diseases Research Centre, University of Queensland, Brisbane, QLD 4072, Australia
| | - Yuri Trusov
- Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
| | - Daisuke Urano
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - David Chakravorty
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Sarah M Assmann
- Department of Biology, Pennsylvania State University, University Park, Pennsylvania 16802, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
- Department of Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599, USA
| | - Jose R Botella
- Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD, 4072, Australia
- Author for communication:
| |
Collapse
|
23
|
Zhang H, Xie P, Xu X, Xie Q, Yu F. Heterotrimeric G protein signalling in plant biotic and abiotic stress response. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23 Suppl 1:20-30. [PMID: 33533569 DOI: 10.1111/plb.13241] [Citation(s) in RCA: 5] [Impact Index Per Article: 1.7] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 01/08/2021] [Accepted: 01/25/2021] [Indexed: 05/20/2023]
Abstract
Heterotrimeric G proteins act as molecular switches to participate in transmitting various stimuli signals from outside of cells. G proteins have three subunits, Gα, Gβ and Gγ, which function mutually to modulate many biological processes in plants, including plant growth and development, as well as biotic and abiotic stress responses. In plants, the number of Gγ subunits is larger than that of the α and β subunits. Based on recent breakthroughs in studies of plant G protein signal perception, transduction and downstream effectors, this review summarizes and analyses the connections between different subunits and the interactions of G proteins with other signalling pathways, especially in plant biotic and abiotic stress responses. Based on current progress and unresolved questions in the field, we also suggest future research directions on G proteins in plants.
Collapse
Affiliation(s)
- H Zhang
- School of Agriculture, Ningxia University, Yinchuan, China
| | - P Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - X Xu
- School of Agriculture, Ningxia University, Yinchuan, China
- Breeding Base of State Key Laboratory of Land Degradation and Ecological Restoration of North Western China, Ningxia University, Yinchuan, China
| | - Q Xie
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| | - F Yu
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, The Innovative Academy of Seed Design, Chinese Academy of Sciences, Beijing, China
| |
Collapse
|
24
|
Ghusinga KR, Paredes F, Jones AM, Colaneri A. Reported differences in the flg22 response of the null mutation of AtRGS1 correlates with fixed genetic variation in the background of Col-0 isolates. PLANT SIGNALING & BEHAVIOR 2021; 16:1878685. [PMID: 33522388 PMCID: PMC7971207 DOI: 10.1080/15592324.2021.1878685] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 05/12/2023]
Abstract
A role for the heterotrimeric G protein complex in the induction of a transient burst of reactive oxygen species (ROS) by the Microbial-Associated Molecular Pattern, flg22, a 22-amino acid peptide derived from bacterial flagella, is well established. However, the evidence for a negative or positive role for one component of the Arabidopsis G protein complex, namely, Regulator of G Signaling 1 (AtRGS1) leads to opposing conclusions. We show that the reason for this difference is due to the isolate of Col-0 ecotype used as the wildtype control in flg22-induced ROS and our data further support the idea that AtRGS1 is a negative regulator of the flg22-induced ROS response. Whole-genome genotyping led to the identification and validation of polymorphism in five genes between two Col-0 isolates that are candidates for the different ROS response relative to the rgs1 null mutant.
Collapse
Affiliation(s)
- Khem Raj Ghusinga
- Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Departments of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
| | - Franco Paredes
- CIFASIS-CONICET-UNR, Ocampo y Esmeralda, Rosario, Argentina
| | - Alan M. Jones
- Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Departments of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- CONTACT Alan M. Jones Departments of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC27599-3280, USA
| | - Alejandro Colaneri
- Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
- Department of Genetics, University of North Carolina at Chapel Hill, Chapel Hill, NC, USA
- Alejandro Colaneri Facultad de Ciencias Médicas, Universidad Nacional de Rosario, Rosario, Argentina
| |
Collapse
|
25
|
Molecular switch architecture determines response properties of signaling pathways. Proc Natl Acad Sci U S A 2021; 118:2013401118. [PMID: 33688042 DOI: 10.1073/pnas.2013401118] [Citation(s) in RCA: 8] [Impact Index Per Article: 2.7] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/27/2022] Open
Abstract
Many intracellular signaling pathways are composed of molecular switches, proteins that transition between two states-on and off Typically, signaling is initiated when an external stimulus activates its cognate receptor that, in turn, causes downstream switches to transition from off to on using one of the following mechanisms: activation, in which the transition rate from the off state to the on state increases; derepression, in which the transition rate from the on state to the off state decreases; and concerted, in which activation and derepression operate simultaneously. We use mathematical modeling to compare these signaling mechanisms in terms of their dose-response curves, response times, and abilities to process upstream fluctuations. Our analysis elucidates several operating principles for molecular switches. First, activation increases the sensitivity of the pathway, whereas derepression decreases sensitivity. Second, activation generates response times that decrease with signal strength, whereas derepression causes response times to increase with signal strength. These opposing features allow the concerted mechanism to not only show dose-response alignment, but also to decouple the response time from stimulus strength. However, these potentially beneficial properties come at the expense of increased susceptibility to upstream fluctuations. We demonstrate that these operating principles also hold when the models are extended to include additional features, such as receptor removal, kinetic proofreading, and cascades of switches. In total, we show how the architecture of molecular switches govern their response properties. We also discuss the biological implications of our findings.
Collapse
|
26
|
Jin YN, Cui ZH, Ma K, Yao JL, Ruan YY, Guo ZF. Characterization of ZmCOLD1, novel GPCR-Type G Protein genes involved in cold stress from Zea mays L. and the evolution analysis with those from other species. PHYSIOLOGY AND MOLECULAR BIOLOGY OF PLANTS : AN INTERNATIONAL JOURNAL OF FUNCTIONAL PLANT BIOLOGY 2021; 27:619-632. [PMID: 33854288 PMCID: PMC7981359 DOI: 10.1007/s12298-021-00966-8] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/21/2020] [Revised: 02/27/2021] [Accepted: 03/03/2021] [Indexed: 06/12/2023]
Abstract
Maize is one of the most vital staple crops worldwide. G proteins modulate plentiful signaling pathways, and G protein-coupled receptor-type G proteins (GPCRs) are highly conserved membrane proteins in plants. However, researches on maize G proteins and GPCRs are scarce. In this study, we identified three novel GPCR-Type G Protein (GTG) genes from chromosome 10 (Chr 10) in maize, designated as ZmCOLD1-10A, ZmCOLD1-10B and ZmCOLD1-10C. Their amino acid sequences had high similarity to TaCOLD1 from wheat and OsCOLD1 from rice. They contained the basic characteristics of GTG/COLD1 proteins, including GPCR-like topology, the conserved hydrophilic loop (HL) domain, DUF3735 (domain of unknown function 3735) domain, GTPase-activating domain, and ATP/GTP-binding domain. Subcellular localization analyses of ZmCOLD1 proteins suggested that ZmCOLD1 proteins localized on plasma membrane (PM) and endoplasmic reticulum (ER). Furthermore, amino acid sequence alignment verified the conservation of the key 187th amino acid T in maize and other wild maize-relative species. Evolutionary relationship among plants GTG/COLD1 proteins family displayed strong group-specificity. Expression analysis indicated that ZmCOLD1-10A was cold-induced and inhibited by light. Together, these results suggested that ZmCOLD1 genes had potential value to improve cold tolerance and to contribute crops growth and molecular breeding.
Collapse
Affiliation(s)
- Ya-Nan Jin
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
- College of Life Science, Inner Mongolia University for the Nationalities, Tongliao, 028000 China
| | - Zhen-hai Cui
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Ke Ma
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Jia-Lu Yao
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Yan-Ye Ruan
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| | - Zhi-Fu Guo
- College of Bioscience and Biotechnology, Shenyang Agricultural University, Shenyang, 110866 China
| |
Collapse
|
27
|
Pathak RR, Mandal VK, Jangam AP, Sharma N, Madan B, Jaiswal DK, Raghuram N. Heterotrimeric G-protein α subunit (RGA1) regulates tiller development, yield, cell wall, nitrogen response and biotic stress in rice. Sci Rep 2021; 11:2323. [PMID: 33504880 PMCID: PMC7840666 DOI: 10.1038/s41598-021-81824-1] [Citation(s) in RCA: 4] [Impact Index Per Article: 1.3] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/15/2020] [Accepted: 01/12/2021] [Indexed: 01/27/2023] Open
Abstract
G-proteins are implicated in plant productivity, but their genome-wide roles in regulating agronomically important traits remain uncharacterized. Transcriptomic analyses of rice G-protein alpha subunit mutant (rga1) revealed 2270 differentially expressed genes (DEGs) including those involved in C/N and lipid metabolism, cell wall, hormones and stress. Many DEGs were associated with root, leaf, culm, inflorescence, panicle, grain yield and heading date. The mutant performed better in total weight of filled grains, ratio of filled to unfilled grains and tillers per plant. Protein–protein interaction (PPI) network analysis using experimentally validated interactors revealed many RGA1-responsive genes involved in tiller development. qPCR validated the differential expression of genes involved in strigolactone-mediated tiller formation and grain development. Further, the mutant growth and biomass were unaffected by submergence indicating its role in submergence response. Transcription factor network analysis revealed the importance of RGA1 in nitrogen signaling with DEGs such as Nin-like, WRKY, NAC, bHLH families, nitrite reductase, glutamine synthetase, OsCIPK23 and urea transporter. Sub-clustering of DEGs-associated PPI network revealed that RGA1 regulates metabolism, stress and gene regulation among others. Predicted rice G-protein networks mapped DEGs and revealed potential effectors. Thus, this study expands the roles of RGA1 to agronomically important traits and reveals their underlying processes.
Collapse
Affiliation(s)
- Ravi Ramesh Pathak
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India
| | - Vikas Kumar Mandal
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India
| | - Annie Prasanna Jangam
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India
| | - Narendra Sharma
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India
| | - Bhumika Madan
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India
| | - Dinesh Kumar Jaiswal
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India.
| | - Nandula Raghuram
- University School of Biotechnology, Guru Gobind Singh Indraprastha University, Sector 16C, Dwarka, New Delhi, 110078, India.
| |
Collapse
|
28
|
Ofoe R. Signal transduction by plant heterotrimeric G-protein. PLANT BIOLOGY (STUTTGART, GERMANY) 2021; 23:3-10. [PMID: 32803877 DOI: 10.1111/plb.13172] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/05/2020] [Accepted: 08/09/2020] [Indexed: 06/11/2023]
Abstract
Heterotrimeric G-proteins are complexes that regulate important signalling pathways essential for growth and development in both plants and animals. Although plant cells are composed of the core components (Gα, Gβ and Gγ subunits) found in animal G-proteins, the complexities of the architecture, function and signalling mechanisms of those in animals are dissimilar to those identified in some plants. Current studies on plant G-proteins have improved knowledge of the essential physiological and agronomic properties, which when harnessed, could potentially impact global food security. Extensive studies on the molecular mechanisms underlying these properties in diverse plant species will be imperative in improving our current understanding of G-protein signalling pathways involved in plant growth and development. The advancement of G-protein signalling networks in distinct plant species could significantly aid in better crop development. This review summarizes current progress, novel discoveries and future prospects for this area in potential crop improvement.
Collapse
Affiliation(s)
- R Ofoe
- Department of Biology and Biochemistry, University of Bath, Bath, UK
- West African Centre for Crop Improvement, University of Ghana, Legon, Accra, Ghana
| |
Collapse
|
29
|
Pandey S. Plant receptor-like kinase signaling through heterotrimeric G-proteins. JOURNAL OF EXPERIMENTAL BOTANY 2020; 71:1742-1751. [PMID: 31930311 PMCID: PMC7242010 DOI: 10.1093/jxb/eraa016] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/18/2019] [Accepted: 01/10/2020] [Indexed: 05/06/2023]
Abstract
Heterotrimeric G-proteins regulate multiple aspects of plant growth, development, and response to biotic and abiotic stresses. While the core components of heterotrimeric G-proteins and their basic biochemistry are similar in plants and metazoans, key differences exist in their regulatory mechanisms. In particular, the activation mechanisms of plant G-proteins appear diverse and may include both canonical and novel modes. Classical G-protein-coupled receptor-like proteins exist in plants and interact with Gα proteins, but their ability to activate Gα by facilitating GDP to GTP exchange has not been demonstrated. Conversely, there is genetic and functional evidence that plant G-proteins interact with the highly prevalent receptor-like kinases (RLKs) and are phosphorylated by them. This suggests the exciting scenario that in plants the G-proteins integrate RLK-dependent signal perception at the plasma membrane with downstream effectors. Because RLKs are active kinases, it is also likely that the activity of plant G-proteins is regulated via phosphorylation/dephosphorylation rather than GTP-GDP exchange as in metazoans. This review discusses our current knowledge of the possible RLK-dependent regulatory mechanisms of plant G-protein signaling in the context of several biological systems and outlines the diversity that might exist in such regulation.
Collapse
Affiliation(s)
- Sona Pandey
- Donald Danforth Plant Science Center, St Louis, MO, USA
- Correspondence:
| |
Collapse
|
30
|
Qiu M, Li Y, Zhang X, Xuan M, Zhang B, Ye W, Zheng X, Govers F, Wang Y. G protein α subunit suppresses sporangium formation through a serine/threonine protein kinase in Phytophthora sojae. PLoS Pathog 2020; 16:e1008138. [PMID: 31961913 PMCID: PMC7010300 DOI: 10.1371/journal.ppat.1008138] [Citation(s) in RCA: 13] [Impact Index Per Article: 3.3] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/13/2019] [Revised: 02/10/2020] [Accepted: 10/09/2019] [Indexed: 02/06/2023] Open
Abstract
Eukaryotic heterotrimeric guanine nucleotide-binding proteins consist of α, β, and γ subunits, which act as molecular switches to regulate a number of fundamental cellular processes. In the oomycete pathogen Phytophthora sojae, the sole G protein α subunit (Gα; encoded by PsGPA1) has been found to be involved in zoospore mobility and virulence, but how it functions remains unclear. In this study, we show that the Gα subunit PsGPA1 directly interacts with PsYPK1, a serine/threonine protein kinase that consists of an N-terminal region with unknown function and a C-terminal region with a conserved catalytic kinase domain. We generated knockout and knockout-complemented strains of PsYPK1 and found that deletion of PsYPK1 resulted in a pronounced reduction in the production of sporangia and oospores, in mycelial growth on nutrient poor medium, and in virulence. PsYPK1 exhibits a cytoplasmic-nuclear localization pattern that is essential for sporangium formation and virulence of P. sojae. Interestingly, PsGPA1 overexpression was found to prevent nuclear localization of PsYPK1 by exclusively binding to the N-terminal region of PsYPK1, therefore accounting for its negative role in sporangium formation. Our data demonstrate that PsGPA1 negatively regulates sporangium formation by repressing the nuclear localization of its downstream kinase PsYPK1.
Collapse
Affiliation(s)
- Min Qiu
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Yaning Li
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Xin Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Mingrun Xuan
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Baiyu Zhang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Wenwu Ye
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Xiaobo Zheng
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| | - Francine Govers
- Laboratory of Phytopathology, Wageningen University, Wageningen, The Netherlands
| | - Yuanchao Wang
- Department of Plant Pathology, Nanjing Agricultural University, Nanjing, Jiangsu, China
- The Key Laboratory of Integrated Management of Crop Diseases and Pests (Ministry of Education), Nanjing, Jiangsu, China
| |
Collapse
|
31
|
Wang W, Feng B, Zhou JM, Tang D. Plant immune signaling: Advancing on two frontiers. JOURNAL OF INTEGRATIVE PLANT BIOLOGY 2020; 62:2-24. [PMID: 31846204 DOI: 10.1111/jipb.12898] [Citation(s) in RCA: 135] [Impact Index Per Article: 33.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 11/21/2019] [Accepted: 12/16/2019] [Indexed: 05/21/2023]
Abstract
Plants have evolved multiple defense strategies to cope with pathogens, among which plant immune signaling that relies on cell-surface localized and intracellular receptors takes fundamental roles. Exciting breakthroughs were made recently on the signaling mechanisms of pattern recognition receptors (PRRs) and intracellular nucleotide-binding site (NBS) and leucine-rich repeat (LRR) domain receptors (NLRs). This review summarizes the current view of PRRs activation, emphasizing the most recent discoveries about PRRs' dynamic regulation and signaling mechanisms directly leading to downstream molecular events including mitogen-activated protein kinase (MAPK) activation and calcium (Ca2+ ) burst. Plants also have evolved intracellular NLRs to perceive the presence of specific pathogen effectors and trigger more robust immune responses. We also discuss the current understanding of the mechanisms of NLR activation, which has been greatly advanced by recent breakthroughs including structures of the first full-length plant NLR complex, findings of NLR sensor-helper pairs and novel biochemical activity of Toll/interleukin-1 receptor (TIR) domain.
Collapse
Affiliation(s)
- Wei Wang
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Baomin Feng
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| | - Jian-Min Zhou
- The State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, Beijing, 100101, China
| | - Dingzhong Tang
- State Key Laboratory of Ecological Control of Fujian-Taiwan Crop Pests, Key Laboratory of Ministry of Education for Genetics, Breeding and Multiple Utilization of Crops, Plant Immunity Center, Fujian Agriculture and Forestry University, Fuzhou, 350002, China
| |
Collapse
|
32
|
Lou F, Abramyan TM, Jia H, Tropsha A, Jones AM. An atypical heterotrimeric Gα protein has substantially reduced nucleotide binding but retains nucleotide-independent interactions with its cognate RGS protein and Gβγ dimer. J Biomol Struct Dyn 2019; 38:5204-5218. [PMID: 31838952 DOI: 10.1080/07391102.2019.1704879] [Citation(s) in RCA: 15] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/25/2022]
Abstract
Plants uniquely have a family of proteins called extra-large G proteins (XLG) that share homology in their C-terminal half with the canonical Gα subunits; we carefully detail here that Arabidopsis XLG2 lacks critical residues requisite for nucleotide binding and hydrolysis which is consistent with our quantitative analyses. Based on microscale thermophoresis, Arabidopsis XLG2 binds GTPγS with an affinity 100 times lower than that to canonical Gα subunits. This means that given the concentration range of guanine nucleotide in plant cells, XLG2 is not likely bound by GTP in vivo. Homology modeling and molecular dynamics simulations provide a plausible mechanism for the poor nucleotide binding affinity of XLG2. Simulations indicate substantially stronger salt bridge networks formed by several key amino-acid residues of AtGPA1 which are either misplaced or missing in XLG2. These residues in AtGPA1 not only maintain the overall shape and integrity of the apoprotein cavity but also increase the frequency of favorable nucleotide-protein interactions in the nucleotide-bound state. Despite this loss of nucleotide dependency, XLG2 binds the RGS domain of AtRGS1 with an affinity similar to the Arabidopsis AtGPA1 in its apo-state and about 2 times lower than AtGPA1 in its transition state. In addition, XLG2 binds the Gβγ dimer with an affinity similar to that of AtGPA1. XLG2 likely acts as a dominant negative Gα protein to block G protein signaling. We propose that XLG2, independent of guanine nucleotide binding, regulates the active state of the canonical G protein pathway directly by sequestering Gβγ and indirectly by promoting heterodimer formation.Communicated by Ramaswamy H. Sarma.
Collapse
Affiliation(s)
- Fei Lou
- Departments of Pharmacology, University of North Carolina at Chapel Hill, NC, USA
| | - Tigran M Abramyan
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - Haiyan Jia
- Departments of Pharmacology, University of North Carolina at Chapel Hill, NC, USA
| | - Alexander Tropsha
- Division of Chemical Biology and Medicinal Chemistry, UNC Eshelman School of Pharmacy, University of North Carolina at Chapel Hill, NC, USA
| | - Alan M Jones
- Departments of Pharmacology, University of North Carolina at Chapel Hill, NC, USA.,Departments of Biology and Pharmacology, University of North Carolina at Chapel Hill, NC, USA
| |
Collapse
|
33
|
Jia H, Song G, Werth EG, Walley JW, Hicks LM, Jones AM. Receptor-Like Kinase Phosphorylation of Arabidopsis Heterotrimeric G-Protein Gα -Subunit AtGPA1. Proteomics 2019; 19:e1900265. [PMID: 31693794 PMCID: PMC7014827 DOI: 10.1002/pmic.201900265] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/13/2019] [Revised: 10/04/2019] [Indexed: 01/07/2023]
Abstract
As molecular on-off switches, heterotrimeric G protein complexes, comprised of a Gα subunit and an obligate Gβγ dimer, transmit extracellular signals received by G protein-coupled receptors (GPCRs) to cytoplasmic targets that respond to biotic and abiotic stimuli. Signal transduction is modulated by phosphorylation of GPCRs and G protein complexes. In Arabidopsis thaliana, the Gα subunit AtGPA1 is phosphorylated by the receptor-like kinase (RLK) BRI1-associated Kinase 1 (BAK1), but the extent that other RLKs phosphorylates AtGPA1 is unknown. Twenty-two trans-phosphorylation sites on AtGPA1 are mapped by 12 RLKs hypothesized to act in the Arabidopsis G protein signaling pathway. Cis-phosphorylation sites are also identified on these RLKs, some newly shown to be dual specific kinases. Multiple sites are present in the core AtGPA1 functional units, including pSer52 and/or pThr53 of the conserved P-loop that directly binds nucleotide/phosphate, pThr164, and pSer175 from αE helix in the intramolecular domain interface for nucleotide exchange and GTP hydrolysis, and pThr193 and/or pThr194 in Switch I (SwI) that coordinates nucleotide exchange and protein partner binding. Several AtGPA1 S/T phosphorylation sites are potentially nucleotide-dependent phosphorylation patterns, such as Ser52/Thr53 in the P-loop and Thr193 and/or Thr194 in SwI.
Collapse
Affiliation(s)
- Haiyan Jia
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Gaoyuan Song
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Emily G Werth
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Justin W Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA, 50011, USA
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
- Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC, 27599, USA
| |
Collapse
|
34
|
Maruta N, Trusov Y, Chakravorty D, Urano D, Assmann SM, Botella JR. Nucleotide exchange-dependent and nucleotide exchange-independent functions of plant heterotrimeric GTP-binding proteins. Sci Signal 2019; 12:12/606/eaav9526. [PMID: 31690635 DOI: 10.1126/scisignal.aav9526] [Citation(s) in RCA: 21] [Impact Index Per Article: 4.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/02/2022]
Abstract
Heterotrimeric guanine nucleotide-binding proteins (G proteins), which are composed of α, β, and γ subunits, are versatile, guanine nucleotide-dependent, molecular on-off switches. In animals and fungi, the exchange of GDP for GTP on Gα controls G protein activation and is crucial for normal cellular responses to diverse extracellular signals. The model plant Arabidopsis thaliana has a single canonical Gα subunit, AtGPA1. We found that, in planta, the constitutively active, GTP-bound AtGPA1(Q222L) mutant and the nucleotide-free AtGPA1(S52C) mutant interacted with Gβγ1 and Gβγ2 dimers with similar affinities, suggesting that G protein heterotrimer formation occurred independently of nucleotide exchange. In contrast, AtGPA1(Q222L) had a greater affinity than that of AtGPA1(S52C) for Gβγ3, suggesting that the GTP-bound conformation of AtGPA1(Q222L) is distinct and tightly associated with Gβγ3. Functional analysis of transgenic lines expressing either AtGPA1(S52C) or AtGPA1(Q222L) in the gpa1-null mutant background revealed various mutant phenotypes that were complemented by either AtGPA1(S52C) or AtGPA1(Q222L). We conclude that, in addition to the canonical GDP-GTP exchange-dependent mechanism, plant G proteins can function independently of nucleotide exchange.
Collapse
Affiliation(s)
- Natsumi Maruta
- Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - Yuri Trusov
- Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia
| | - David Chakravorty
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Daisuke Urano
- Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, Singapore 117604, Singapore
| | - Sarah M Assmann
- Department of Biology, Pennsylvania State University, University Park, PA 16802, USA
| | - Jose R Botella
- Plant Genetic Engineering Laboratory, School of Agriculture and Food Sciences, University of Queensland, Brisbane, QLD 4072, Australia. .,State Key Laboratory of Cotton Biology, Department of Biology, Institute of Plant Stress Biology, Henan University, Kaifeng 475001, China
| |
Collapse
|
35
|
Jiao Y, Srba M, Wang J, Chen W. Correlation of Autophagosome Formation with Degradation and Endocytosis Arabidopsis Regulator of G-Protein Signaling (RGS1) through ATG8a. Int J Mol Sci 2019; 20:ijms20174190. [PMID: 31461856 PMCID: PMC6747245 DOI: 10.3390/ijms20174190] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 07/05/2019] [Revised: 08/20/2019] [Accepted: 08/26/2019] [Indexed: 12/30/2022] Open
Abstract
Damaged or unwanted cellular proteins are degraded by either autophagy or the ubiquitin/proteasome pathway. In Arabidopsis thaliana, sensing of D-glucose is achieved by the heterotrimeric G protein complex and regulator of G-protein signaling 1 (AtRGS1). Here, we showed that starvation increases proteasome-independent AtRGS1 degradation, and it is correlated with increased autophagic flux. RGS1 promoted the production of autophagosomes and autophagic flux; RGS1-yellow fluorescent protein (YFP) was surrounded by vacuolar dye FM4-64 (red fluorescence). RGS1 and autophagosomes co-localized in the root cells of Arabidopsis and BY-2 cells. We demonstrated that the autophagosome marker ATG8a interacts with AtRGS1 and its shorter form with truncation of the seven transmembrane and RGS1 domains in planta. Altogether, our data indicated the correlation of autophagosome formation with degradation and endocytosis of AtRGS1 through ATG8a.
Collapse
Affiliation(s)
- Yue Jiao
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
- College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Miroslav Srba
- Department of Experimental Plant Biology, Faculty of Science, Charles University, 12844 Prague, Czech Republic
| | - Jingchun Wang
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China
- College of Biophotonics, South China Normal University, Guangzhou 510631, China
| | - Wenli Chen
- MOE Key Laboratory of Laser Life Science & Institute of Laser Life Science, South China Normal University, Guangzhou 510631, China.
- College of Biophotonics, South China Normal University, Guangzhou 510631, China.
| |
Collapse
|
36
|
Gao Y, Gu H, Leburu M, Li X, Wang Y, Sheng J, Fang H, Gu M, Liang G. The heterotrimeric G protein β subunit RGB1 is required for seedling formation in rice. RICE (NEW YORK, N.Y.) 2019; 12:53. [PMID: 31321558 PMCID: PMC6639528 DOI: 10.1186/s12284-019-0313-y] [Citation(s) in RCA: 16] [Impact Index Per Article: 3.2] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 04/11/2019] [Accepted: 07/08/2019] [Indexed: 05/22/2023]
Abstract
BACKGROUND The heterotrimeric G protein β subunit RGB1 plays an important role in plant growth and development. However, the molecular mechanisms underlying the regulation of rice growth by RGB1 remain elusive. RESULTS Here, the rgb1 mutants rgb1-1 (+ 1 bp), rgb1-2 (- 1 bp), and rgb1-3 (- 11 bp) were isolated using the CRISPR/Cas9 system, and they were arrested at 1 day after germination and ultimately exhibited seedling lethality. The dynamic anatomical characteristics of the embryos of the rgb1 seedlings and WT during early postgermination and according to TUNEL assays showed that the suppressed growth of the rgb1 mutants was caused by cell death. In addition to the limited shoot and root development, the development of the embryo shoot-root axis was suppressed in the rgb1 mutants. RGB1 was expressed mainly in the root epidermal and vascular tissues of the embryo. Moreover, transcript profiling analysis revealed that the expression of a large number of auxin-, cytokinin-, and brassinosteroid-inducible genes was upregulated or downregulated in the rgb1 mutant compared to the wild type during seedling development. CONCLUSIONS Overall, the rgb1 mutants provide an ideal material for exploring the molecular mechanism underlying rice seedling formation during early postgermination development by G proteins. SIGNIFICANCE STATEMENT The heterotrimeric G protein β subunit RGB1 acts as a crucial factor in promoting early postgermination seedling development in rice.
Collapse
Affiliation(s)
- Yun Gao
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Houwen Gu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Mamotshewa Leburu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Xuhui Li
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Yan Wang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Jiayan Sheng
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Huimin Fang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Minghong Gu
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China
| | - Guohua Liang
- Jiangsu Key Laboratory of Crop Genetics and Physiology/Key Laboratory of Plant Functional Genomics of the Ministry of Education/Jiangsu Key Laboratory of Crop Genomics and Molecular Breeding, Jiangsu Co-Innovation Center for Modern Production Technology of Grain Crops, Agricultural College, Yangzhou University, Yangzhou, 225009, China.
| |
Collapse
|
37
|
Biswal AK, McConnell EW, Werth EG, Lo SF, Yu SM, Hicks LM, Jones AM. The Nucleotide-Dependent Interactome of Rice Heterotrimeric G-Protein α -Subunit. Proteomics 2019; 19:e1800385. [PMID: 30866160 DOI: 10.1002/pmic.201800385] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/05/2018] [Revised: 02/12/2019] [Indexed: 11/09/2022]
Abstract
The rice heterotrimeric G-protein complex, a guanine-nucleotide-dependent on-off switch, mediates vital cellular processes and responses to biotic and abiotic stress. Exchange of bound GDP (resting state) for GTP (active state) is spontaneous in plants including rice and thus there is no need for promoting guanine nucleotide exchange in vivo as a mechanism for regulating the active state of signaling as it is well known for animal G signaling. As such, a master regulator controlling the G-protein activation state is unknown in plants. Therefore, an ab initio approach is taken to discover candidate regulators. The rice Gα subunit (RGA1) is used as bait to screen for nucleotide-dependent protein partners. A total of 264 proteins are identified by tandem mass spectrometry of which 32 were specific to the GDP-bound inactive state and 22 specific to the transition state. Approximately, 10% are validated as previously identified G-protein interactors.
Collapse
Affiliation(s)
- Akshaya Kumar Biswal
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Evan Wesley McConnell
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Emily Grace Werth
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Shuen-Fang Lo
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, China
| | - Su-May Yu
- Institute of Molecular Biology, Academia Sinica, Nankang, Taipei, Taiwan, China
| | - Leslie M Hicks
- Department of Chemistry, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| | - Alan M Jones
- Department of Biology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA.,Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, NC 27599, USA
| |
Collapse
|
38
|
Dong H, Yan S, Liu J, Liu P, Sun J. TaCOLD1 defines a new regulator of plant height in bread wheat. PLANT BIOTECHNOLOGY JOURNAL 2019; 17:687-699. [PMID: 30183124 PMCID: PMC6381784 DOI: 10.1111/pbi.13008] [Citation(s) in RCA: 6] [Impact Index Per Article: 1.2] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/02/2018] [Revised: 08/14/2018] [Accepted: 08/23/2018] [Indexed: 05/21/2023]
Abstract
Plant height is among the most important agronomic traits that influence crop yield. However, in addition to the Rht-1 alleles, the molecular basis of plant height in bread wheat remains largely unclear. Based on wheat gene expression profiling analysis, we identify a light-regulated gene from bread wheat, designated as TaCOLD1, whose encoding protein is homologous to cold sensor COLD1 in rice. We show that TaCOLD1 protein is localized to the endoplasmic reticulum (ER) and plasma membrane. Phenotypic analyses show that overexpression of a mutated form of TaCOLD1 (M187K) in bread wheat cultivar Kenong199 (Rht-B1b) background resulted in an obvious reduction in plant height. Further, we demonstrate that the hydrophilic loop of TaCOLD1 (residues 178-296) can interact with TaGα-7A (the α subunit of heterotrimeric G protein) protein but not TaGα-1B, and the mutation (M187K) in TaCOLD1 remarkably enhances its interaction with TaGα-7A. Physical interaction analyses show that the C-terminal region of TaGα-7A, which is lacking in the TaGα-1B protein, is necessary for its interaction with TaCOLD1. Intriguingly, the C-terminal region of TaGα-7A is also physically associated with the TaDEP1 protein (an atypical Gγ subunit). Significantly, we discover that TaCOLD1 and mTaCOLD1 (M187K) can interfere with the physical association between TaGα-7A and TaDEP1. Together, this study reveals that TaCOLD1 acts as a novel regulator of plant height through interfering with the formation of heterotrimeric G protein complex in bread wheat and is a valuable target for the engineering of wheat plant architecture.
Collapse
Affiliation(s)
- Huixue Dong
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Suli Yan
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Jie Liu
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Pan Liu
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| | - Jiaqiang Sun
- National Key Facility for Crop Gene Resources and Genetic ImprovementInstitute of Crop SciencesChinese Academy of Agricultural SciencesBeijingChina
| |
Collapse
|
39
|
Zhong CL, Zhang C, Liu JZ. Heterotrimeric G protein signaling in plant immunity. JOURNAL OF EXPERIMENTAL BOTANY 2019; 70:1109-1118. [PMID: 30481338 DOI: 10.1093/jxb/ery426] [Citation(s) in RCA: 30] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/12/2018] [Accepted: 11/22/2018] [Indexed: 05/26/2023]
Abstract
In animals, heterotrimeric guanine nucleotide-binding proteins (G proteins) transduce signals perceived by numerous G protein-coupled receptors (GPCRs). However, no canonical GPCRs with guanine nucleotide exchange factor (GEF) activity are present in plant genomes. Accumulated evidence indicates that, instead of GPCRs, the receptor-like kinases (RLKs) function upstream of G proteins in plants. Regulator of G protein signaling 1 (RGS1) functions to convert the GTP-bound Gα to the GDP-bound form through its GTPase-accelerating protein (GAP) activity. Because of the intrinsic differences in the biochemical properties between Arabidopsis and animal Gα, the actions of animal and Arabidopsis RGS1 result in contrasting outcomes in G signaling activation/deactivation. Animal RGSs accelerate the deactivation of the activated G signaling, whereas Arabidopsis RGS1 prevents the activation of G signaling in the resting state. Phosphorylation of Arabidopsis RGS1 triggered by ligand-RLK recognition results in the endocytosis or degradation of RGS1, leading to the separation of RGS1 from Gα and thus the derepression of G signaling. Here, we summarize the involvement of the G proteins in plant immunity, with a special focus on the molecular mechanism of G signaling activation/deactivation regulated by RLKs and RGS1. We also provide a brief perspective on the outstanding questions that need to be addressed to fully understand G signaling in plant immunity.
Collapse
Affiliation(s)
- Chen-Li Zhong
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, China
| | - Chi Zhang
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, China
| | - Jian-Zhong Liu
- College of Chemistry and Life Sciences, Zhejiang Normal University, Jinhua, Zhejiang, China
| |
Collapse
|
40
|
Malfacini D, Patt J, Annala S, Harpsøe K, Eryilmaz F, Reher R, Crüsemann M, Hanke W, Zhang H, Tietze D, Gloriam DE, Bräuner-Osborne H, Strømgaard K, König GM, Inoue A, Gomeza J, Kostenis E. Rational design of a heterotrimeric G protein α subunit with artificial inhibitor sensitivity. J Biol Chem 2019; 294:5747-5758. [PMID: 30745359 PMCID: PMC6463727 DOI: 10.1074/jbc.ra118.007250] [Citation(s) in RCA: 22] [Impact Index Per Article: 4.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 12/20/2018] [Revised: 01/28/2019] [Indexed: 12/31/2022] Open
Abstract
Transmembrane signals initiated by a range of extracellular stimuli converge on members of the Gq family of heterotrimeric G proteins, which relay these signals in target cells. Gq family G proteins comprise Gq, G11, G14, and G16, which upon activation mediate their cellular effects via inositol lipid–dependent and –independent signaling to control fundamental processes in mammalian physiology. To date, highly specific inhibition of Gq/11/14 signaling can be achieved only with FR900359 (FR) and YM-254890 (YM), two naturally occurring cyclic depsipeptides. To further development of FR or YM mimics for other Gα subunits, we here set out to rationally design Gα16 proteins with artificial FR/YM sensitivity by introducing an engineered depsipeptide-binding site. Thereby we permit control of G16 function through ligands that are inactive on the WT protein. Using CRISPR/Cas9-generated Gαq/Gα11-null cells and loss- and gain-of-function mutagenesis along with label-free whole-cell biosensing, we determined the molecular coordinates for FR/YM inhibition of Gq and transplanted these to FR/YM-insensitive G16. Intriguingly, despite having close structural similarity, FR and YM yielded biologically distinct activities: it was more difficult to perturb Gq inhibition by FR and easier to install FR inhibition onto G16 than perturb or install inhibition with YM. A unique hydrophobic network utilized by FR accounted for these unexpected discrepancies. Our results suggest that non-Gq/11/14 proteins should be amenable to inhibition by FR scaffold–based inhibitors, provided that these inhibitors mimic the interaction of FR with Gα proteins harboring engineered FR-binding sites.
Collapse
Affiliation(s)
- Davide Malfacini
- From the Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Julian Patt
- From the Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Suvi Annala
- From the Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Kasper Harpsøe
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Funda Eryilmaz
- From the Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Raphael Reher
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Max Crüsemann
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Wiebke Hanke
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Hang Zhang
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Daniel Tietze
- Eduard Zintl Institute of Inorganic and Physical Chemistry, Technische Universität Darmstadt, 64287 Darmstadt, Germany
| | - David E Gloriam
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Hans Bräuner-Osborne
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Kristian Strømgaard
- Department of Drug Design and Pharmacology, University of Copenhagen, Universitetsparken 2, 2100 Copenhagen, Denmark
| | - Gabriele M König
- Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Asuka Inoue
- Graduate School of Pharmaceutical Sciences, Tohoku University, 6-3 Aoba, Aramaki, Aoba-ku, Sendai, Miyagi 980-8578, Japan
| | - Jesus Gomeza
- From the Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany
| | - Evi Kostenis
- From the Molecular, Cellular and Pharmacobiology Section, Institute for Pharmaceutical Biology, University of Bonn, Nussallee 6, 53115 Bonn, Germany.
| |
Collapse
|
41
|
Song G, Brachova L, Nikolau BJ, Jones AM, Walley JW. Heterotrimeric G-Protein-Dependent Proteome and Phosphoproteome in Unstimulated Arabidopsis Roots. Proteomics 2018; 18:e1800323. [PMID: 30407730 PMCID: PMC6298806 DOI: 10.1002/pmic.201800323] [Citation(s) in RCA: 17] [Impact Index Per Article: 2.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/25/2018] [Revised: 10/09/2018] [Indexed: 12/19/2022]
Abstract
The G-protein complex is a cytoplasmic on-off molecular switch that is set by plasma membrane receptors that activate upon binding of its cognate extracellular agonist. In animals, the default setting is the "off" resting state, while in plants, the default state is constitutively "on" but repressed by a plasma membrane receptor-like protein. De-repression appears to involve specific phosphorylation of key elements of the G-protein complex and possibly target proteins that are positioned downstream of this complex. To address this possibility, protein abundance and phosphorylation state are quantified in wild type and G-protein deficient Arabidopsis roots in the unstimulated resting state. A total of 3246 phosphorylated and 8141 non-modified protein groups are identified. It has been found that 428 phosphorylation sites decrease and 509 sites increase in abundance in the G-protein quadrupole mutant lacking an operable G-protein-complex. Kinases with known roles in G-protein signaling including MAP KINASE 6 and FERONIA are differentially phosphorylated along with many other proteins now implicated in the control of G-protein signaling. Taken together, these datasets will enable the discovery of novel proteins and biological processes dependent on G-protein signaling.
Collapse
Affiliation(s)
- Gaoyuan Song
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA USA
| | - Libuse Brachova
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Basil J. Nikolau
- Department of Biochemistry, Biophysics and Molecular Biology, Iowa State University, Ames, IA, USA
| | - Alan M. Jones
- Department of Biology and Department of Pharmacology, University of North Carolina at Chapel Hill, Chapel Hill, North Carolina, USA
| | - Justin W. Walley
- Department of Plant Pathology and Microbiology, Iowa State University, Ames, IA USA
| |
Collapse
|
42
|
G protein subunit phosphorylation as a regulatory mechanism in heterotrimeric G protein signaling in mammals, yeast, and plants. Biochem J 2018; 475:3331-3357. [PMID: 30413679 DOI: 10.1042/bcj20160819] [Citation(s) in RCA: 36] [Impact Index Per Article: 6.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/19/2018] [Revised: 09/28/2018] [Accepted: 10/02/2018] [Indexed: 12/15/2022]
Abstract
Heterotrimeric G proteins composed of Gα, Gβ, and Gγ subunits are vital eukaryotic signaling elements that convey information from ligand-regulated G protein-coupled receptors (GPCRs) to cellular effectors. Heterotrimeric G protein-based signaling pathways are fundamental to human health [Biochimica et Biophysica Acta (2007) 1768, 994-1005] and are the target of >30% of pharmaceuticals in clinical use [Biotechnology Advances (2013) 31, 1676-1694; Nature Reviews Drug Discovery (2017) 16, 829-842]. This review focuses on phosphorylation of G protein subunits as a regulatory mechanism in mammals, budding yeast, and plants. This is a re-emerging field, as evidence for phosphoregulation of mammalian G protein subunits from biochemical studies in the early 1990s can now be complemented with contemporary phosphoproteomics and genetic approaches applied to a diversity of model systems. In addition, new evidence implicates a family of plant kinases, the receptor-like kinases, which are monophyletic with the interleukin-1 receptor-associated kinase/Pelle kinases of metazoans, as possible GPCRs that signal via subunit phosphorylation. We describe early and modern observations on G protein subunit phosphorylation and its functional consequences in these three classes of organisms, and suggest future research directions.
Collapse
|
43
|
Velimezi G, Robinson-Garcia L, Muñoz-Martínez F, Wiegant WW, Ferreira da Silva J, Owusu M, Moder M, Wiedner M, Rosenthal SB, Fisch KM, Moffat J, Menche J, van Attikum H, Jackson SP, Loizou JI. Map of synthetic rescue interactions for the Fanconi anemia DNA repair pathway identifies USP48. Nat Commun 2018; 9:2280. [PMID: 29891926 PMCID: PMC5996029 DOI: 10.1038/s41467-018-04649-z] [Citation(s) in RCA: 23] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2017] [Accepted: 05/14/2018] [Indexed: 01/26/2023] Open
Abstract
Defects in DNA repair can cause various genetic diseases with severe pathological phenotypes. Fanconi anemia (FA) is a rare disease characterized by bone marrow failure, developmental abnormalities, and increased cancer risk that is caused by defective repair of DNA interstrand crosslinks (ICLs). Here, we identify the deubiquitylating enzyme USP48 as synthetic viable for FA-gene deficiencies by performing genome-wide loss-of-function screens across a panel of human haploid isogenic FA-defective cells (FANCA, FANCC, FANCG, FANCI, FANCD2). Thus, as compared to FA-defective cells alone, FA-deficient cells additionally lacking USP48 are less sensitive to genotoxic stress induced by ICL agents and display enhanced, BRCA1-dependent, clearance of DNA damage. Consequently, USP48 inactivation reduces chromosomal instability of FA-defective cells. Our results highlight a role for USP48 in controlling DNA repair and suggest it as a potential target that could be therapeutically exploited for FA.
Collapse
Affiliation(s)
- Georgia Velimezi
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Lydia Robinson-Garcia
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Francisco Muñoz-Martínez
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Wouter W Wiegant
- Department of Human Genetics, Leiden University Medical Center, Leiden, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands
| | - Joana Ferreira da Silva
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Michel Owusu
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Martin Moder
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Marc Wiedner
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Sara Brin Rosenthal
- Center for Computational Biology & Bioinformatics, Department of Medicine, University of California, San Diego, 9500 Gilman Drive #0681, La Jolla, CA, 92093, USA
| | - Kathleen M Fisch
- Center for Computational Biology & Bioinformatics, Department of Medicine, University of California, San Diego, 9500 Gilman Drive #0681, La Jolla, CA, 92093, USA
| | - Jason Moffat
- Donnelly Centre and Banting and Best Department of Medical Research, University of Toronto, Toronto, ON, M5S 1A8, Canada
| | - Jörg Menche
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria
| | - Haico van Attikum
- Department of Human Genetics, Leiden University Medical Center, Leiden, Einthovenweg 20, 2333 ZC, Leiden, The Netherlands
| | - Stephen P Jackson
- The Gurdon Institute and Department of Biochemistry, University of Cambridge, Tennis Court Road, Cambridge, CB2 1QN, UK
| | - Joanna I Loizou
- CeMM Research Center for Molecular Medicine of the Austrian Academy of Sciences, Lazarettgasse 14, AKH BT 25.3, 1090, Vienna, Austria.
| |
Collapse
|
44
|
Bender KW, Zipfel C. Plant G-protein activation: connecting to plant receptor kinases. Cell Res 2018; 28:697-698. [PMID: 29844582 DOI: 10.1038/s41422-018-0046-2] [Citation(s) in RCA: 4] [Impact Index Per Article: 0.7] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/09/2022] Open
Affiliation(s)
- Kyle W Bender
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK, NR4 7UH
| | - Cyril Zipfel
- The Sainsbury Laboratory, Norwich Research Park, Norwich, UK, NR4 7UH.
| |
Collapse
|
45
|
Pandey S, Vijayakumar A. Emerging themes in heterotrimeric G-protein signaling in plants. PLANT SCIENCE : AN INTERNATIONAL JOURNAL OF EXPERIMENTAL PLANT BIOLOGY 2018; 270:292-300. [PMID: 29576082 DOI: 10.1016/j.plantsci.2018.03.001] [Citation(s) in RCA: 12] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 12/05/2017] [Revised: 01/18/2018] [Accepted: 03/01/2018] [Indexed: 05/28/2023]
Abstract
Heterotrimeric G-proteins are key signaling components involved during the regulation of a multitude of growth and developmental pathways in all eukaryotes. Although the core proteins (Gα, Gβ, Gγ subunits) and their basic biochemistries are conserved between plants and non-plant systems, seemingly different inherent properties of specific components, altered wirings of G-protein network architectures, and the presence of novel receptors and effector proteins make plant G-protein signaling mechanisms somewhat distinct from the well-established animal paradigm. G-protein research in plants is getting a lot of attention recently due to the emerging roles of these proteins in controlling many agronomically important traits. New findings on both canonical and novel G-protein components and their conserved and unique signaling mechanisms are expected to improve our understanding of this important module in affecting critical plant growth and development pathways and eventually their utilization to produce plants for the future needs. In this review, we briefly summarize what is currently known in plant G-protein research, describe new findings and how they are changing our perceptions of the field, and discuss important issues that still need to be addressed.
Collapse
Affiliation(s)
- Sona Pandey
- Donald Danforth Plant Science Center, 975 N. Warson Road, St. Louis, MO, 63132, USA.
| | - Anitha Vijayakumar
- Donald Danforth Plant Science Center, 975 N. Warson Road, St. Louis, MO, 63132, USA
| |
Collapse
|
46
|
Liang X, Ma M, Zhou Z, Wang J, Yang X, Rao S, Bi G, Li L, Zhang X, Chai J, Chen S, Zhou JM. Ligand-triggered de-repression of Arabidopsis heterotrimeric G proteins coupled to immune receptor kinases. Cell Res 2018; 28:529-543. [PMID: 29545645 PMCID: PMC5951851 DOI: 10.1038/s41422-018-0027-5] [Citation(s) in RCA: 70] [Impact Index Per Article: 11.7] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/12/2018] [Revised: 02/11/2018] [Accepted: 02/22/2018] [Indexed: 02/01/2023] Open
Abstract
Arabidopsis heterotrimeric G proteins regulate diverse processes by coupling to single-transmembrane receptors. One such receptor is the FLS2 receptor kinase, which perceives bacterial flagellin epitope flg22 to activate immunity through a class of cytoplasmic kinases called BIK1/PBLs. Unlike animal and fungal heterotrimeric G proteins that are activated by a ligand-induced guanine nucleotide exchange activity of seven-transmembrane G protein-coupled receptors (GPCRs), plant heterotrimeric G proteins are self-activating. How plant receptors regulate heterotrimeric G proteins in response to external ligands remains unknown. Here we show that RGS1, a GTPase accelerating protein, maintains Arabidopsis G proteins in an inactive state in complex with FLS2. Activation of FLS2 by flg22 induces a BIK1/PBL-mediated phosphorylation of RGS1 at Ser428 and Ser431 and that promotes RGS1 dissociation from the FLS2-G protein complex. This relieves G proteins from the RGS1-mediated repression and enables positive regulation of immune signaling. We additionally show that RGS1 is similarly regulated by multiple immune receptors. Our results uncover ligand-induced de-repression as a mechanism for G protein signaling in plants that is distinct from previously reported mechanism underlying the activation of heterotrimeric G proteins in other systems.
Collapse
Affiliation(s)
- Xiangxiu Liang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.,State Key Laboratory of Plant Genomics, Institute of Microbiology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Miaomiao Ma
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China.,University of Chinese Academy of Sciences, 100049, Beijing, China
| | - Zhaoyang Zhou
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Jinlong Wang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Xinru Yang
- Center for Plant Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - Shaofei Rao
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Guozhi Bi
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Lin Li
- National Institute of Biological Sciences, 102206, Beijing, China
| | - Xiaojuan Zhang
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China
| | - Jijie Chai
- Center for Plant Biology, School of Life Sciences, Tsinghua University, 100084, Beijing, China
| | - She Chen
- National Institute of Biological Sciences, 102206, Beijing, China
| | - Jian-Min Zhou
- State Key Laboratory of Plant Genomics, Institute of Genetics and Developmental Biology, Chinese Academy of Sciences, 100101, Beijing, China. .,University of Chinese Academy of Sciences, 100049, Beijing, China.
| |
Collapse
|
47
|
Duplicated RGS (Regulator of G-protein signaling) proteins exhibit conserved biochemical but differential transcriptional regulation of heterotrimeric G-protein signaling in Brassica species. Sci Rep 2018; 8:2176. [PMID: 29391473 PMCID: PMC5794992 DOI: 10.1038/s41598-018-20500-3] [Citation(s) in RCA: 5] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/20/2017] [Accepted: 01/18/2018] [Indexed: 12/18/2022] Open
Abstract
G-alpha (Gα) and ‘Regulator of G-protein Signaling (RGS)’ proteins are the two key components primarily involved in regulation of heterotrimeric G-proteins signaling across phyla. Unlike Arabidopsis thaliana, our knowledge about G-protein regulation in polyploid Brassica species is sparse. In this study, we identified one Gα and two RGS genes each from three species of Brassica ‘U’ triangle and assessed the effects of whole genome triplication on the divergence of gene sequence and structure, protein-protein interaction, biochemical activities, and gene expression. Sequence and phylogenetic analysis revealed that the deduced Gα and RGS proteins are evolutionarily conserved across Brassica species. The duplicated RGS proteins of each Brassica species interacted with their cognate Gα but displayed varying levels of interaction strength. The Gα and the duplicated RGS proteins of Brassica species exhibited highly conserved G-protein activities when tested under in-vitro conditions. Expression analysis of the B. rapa RGS genes revealed a high degree of transcriptional differentiation across the tested tissue types and in response to various elicitors, particularly under D-glucose, salt and phytohormone treatments. Taken together, our results suggest that the RGS-mediated regulation of G-protein signaling in Brassica species is predominantly governed by stage and condition-specific expression differentiation of the duplicated RGS genes.
Collapse
|
48
|
Li B, Tunc-Ozdemir M, Urano D, Jia H, Werth EG, Mowrey DD, Hicks LM, Dokholyan NV, Torres MP, Jones AM. Tyrosine phosphorylation switching of a G protein. J Biol Chem 2018; 293:4752-4766. [PMID: 29382719 DOI: 10.1074/jbc.ra117.000163] [Citation(s) in RCA: 18] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/27/2017] [Revised: 01/26/2018] [Indexed: 01/08/2023] Open
Abstract
Heterotrimeric G protein complexes are molecular switches relaying extracellular signals sensed by G protein-coupled receptors (GPCRs) to downstream targets in the cytoplasm, which effect cellular responses. In the plant heterotrimeric GTPase cycle, GTP hydrolysis, rather than nucleotide exchange, is the rate-limiting reaction and is accelerated by a receptor-like regulator of G signaling (RGS) protein. We hypothesized that posttranslational modification of the Gα subunit in the G protein complex regulates the RGS-dependent GTPase cycle. Our structural analyses identified an invariant phosphorylated tyrosine residue (Tyr166 in the Arabidopsis Gα subunit AtGPA1) located in the intramolecular domain interface where nucleotide binding and hydrolysis occur. We also identified a receptor-like kinase that phosphorylates AtGPA1 in a Tyr166-dependent manner. Discrete molecular dynamics simulations predicted that phosphorylated Tyr166 forms a salt bridge in this interface and potentially affects the RGS protein-accelerated GTPase cycle. Using a Tyr166 phosphomimetic substitution, we found that the cognate RGS protein binds more tightly to the GDP-bound Gα substrate, consequently reducing its ability to accelerate GTPase activity. In conclusion, we propose that phosphorylation of Tyr166 in AtGPA1 changes the binding pattern with AtRGS1 and thereby attenuates the steady-state rate of the GTPase cycle. We coin this newly identified mechanism "substrate phosphoswitching."
Collapse
Affiliation(s)
- Bo Li
- Departments of Biology, Chapel Hill, North Carolina 27599
| | | | - Daisuke Urano
- Departments of Biology, Chapel Hill, North Carolina 27599; Temasek Life Sciences Laboratory, 1 Research Link, National University of Singapore, 117604, Singapore
| | - Haiyan Jia
- Departments of Biology, Chapel Hill, North Carolina 27599
| | - Emily G Werth
- Department of Chemistry, Chapel Hill, North Carolina 27599
| | - David D Mowrey
- Biochemistry/Biophysics, Chapel Hill, North Carolina 27599
| | - Leslie M Hicks
- Department of Chemistry, Chapel Hill, North Carolina 27599
| | | | - Matthew P Torres
- Department of Biological Sciences, Georgia Institute of Technology, Atlanta, Georgia 30332
| | - Alan M Jones
- Departments of Biology, Chapel Hill, North Carolina 27599; Pharmacology, University of North Carolina, Chapel Hill, North Carolina 27599.
| |
Collapse
|
49
|
Tanabe S, Aoyagi K, Yokozaki H, Sasaki H. Molecular pathway network of EFNA1 in cancer and mesenchymal stem cells. ACTA ACUST UNITED AC 2018. [DOI: 10.3934/celltissue.2018.2.58] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/14/2022]
|
50
|
Hackenberg D, McKain MR, Lee SG, Roy Choudhury S, McCann T, Schreier S, Harkess A, Pires JC, Wong GKS, Jez JM, Kellogg EA, Pandey S. Gα and regulator of G-protein signaling (RGS) protein pairs maintain functional compatibility and conserved interaction interfaces throughout evolution despite frequent loss of RGS proteins in plants. THE NEW PHYTOLOGIST 2017; 216:562-575. [PMID: 27634188 DOI: 10.1111/nph.14180] [Citation(s) in RCA: 8] [Impact Index Per Article: 1.1] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/10/2016] [Accepted: 08/03/2016] [Indexed: 05/05/2023]
Abstract
Signaling pathways regulated by heterotrimeric G-proteins exist in all eukaryotes. The regulator of G-protein signaling (RGS) proteins are key interactors and critical modulators of the Gα protein of the heterotrimer. However, while G-proteins are widespread in plants, RGS proteins have been reported to be missing from the entire monocot lineage, with two exceptions. A single amino acid substitution-based adaptive coevolution of the Gα:RGS proteins was proposed to enable the loss of RGS in monocots. We used a combination of evolutionary and biochemical analyses and homology modeling of the Gα and RGS proteins to address their expansion and its potential effects on the G-protein cycle in plants. Our results show that RGS proteins are widely distributed in the monocot lineage, despite their frequent loss. There is no support for the adaptive coevolution of the Gα:RGS protein pair based on single amino acid substitutions. RGS proteins interact with, and affect the activity of, Gα proteins from species with or without endogenous RGS. This cross-functional compatibility expands between the metazoan and plant kingdoms, illustrating striking conservation of their interaction interface. We propose that additional proteins or alternative mechanisms may exist which compensate for the loss of RGS in certain plant species.
Collapse
Affiliation(s)
- Dieter Hackenberg
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| | - Michael R McKain
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| | - Soon Goo Lee
- Department of Biology, Washington University, One Brookings Drive, Campus Box 1137, St Louis, MO, 63130, USA
| | - Swarup Roy Choudhury
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| | - Tyler McCann
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| | - Spencer Schreier
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| | - Alex Harkess
- Department of Plant Biology, University of Georgia, Athens, GA, 30602, USA
| | - J Chris Pires
- Interdisciplinary Plant Group, University of Missouri, Columbia, MO, 65211, USA
| | - Gane Ka-Shu Wong
- Department of Biological Sciences, University of Alberta, Edmonton, AB, T6G 2E9, Canada
- Department of Medicine, University of Alberta, Edmonton, AB, T6G 2E1, Canada
- BGI-Shenzhen, Beishan Industrial Zone, Yantian District, Shenzhen, 518083, China
| | - Joseph M Jez
- Department of Biology, Washington University, One Brookings Drive, Campus Box 1137, St Louis, MO, 63130, USA
| | - Elizabeth A Kellogg
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| | - Sona Pandey
- Donald Danforth Plant Science Center, 975 North Warson Road, St Louis, MO, 63132, USA
| |
Collapse
|